Ventricular Tachycardia Induced by Propafenone Intoxication in a Pediatric Patient

Formulation and stability of an extemporaneously compounded propafenone hydrochloride oral suspension for children with arrhythmia

OBJECTIVES

In children, supraventricular tachycardia is the most common form of arrhythmia, and propafenone is an effective class Ic antiarrhythmic agent used in this population. No suitable paediatric-specific, dosing-flexible preparation is available in Taiwan. The objective of this study was to develop a formulation of propafenone oral suspension prepared from commercially available propafenone tablets and commercially available oral syrup vehicles for related patients.

METHODS

An oral suspension of propafenone hydrochloride at a concentration of 10 mg/mL was prepared by mixing finely grounded propafenone hydrochloride tablets and a 1:1 mixture of Ora-Plus and Ora-Sweet. The beyond-use date was determined by analysing the samples stored at room temperature or 2-8℃ at time 0 and on days 7, 14, 21, 28, 35, 42, 56, and 90. Parameters to be inspected included appearance, pH measurement, high-performance liquid chromatography analysis, and microbial limit tests.

RESULTS

On the basis of the physicochemical and microbial stability results, the 10 mg/mL oral suspension of propafenone hydrochloride was stable at 2-8℃ and room temperature for at least 90 days. The suspension did not exhibit significant changes in drug concentration or pH level at any time point. Moreover, no apparent changes or microbial contaminations were observed for at least 90 days.

CONCLUSIONS

Propafenone hydrochloride in a 10 mg/mL oral suspension prepared by diluting fine powder with a 1:1 mixture of Ora-Plus and Ora-Sweet and stored in high-density polyethylene bottles and has a beyond-use date of 90 days when stored at 2-8℃ or room temperature. This finding enables us to improve the accuracy of dosage administration and reduce the risk of medication errors affecting the paediatric population.

Frequent torsades de pointes in a child with novel AKAP9 mutation: A case report and literature review

INTRODUCTION

The aim of the present study is to report the diagnosis and treatment of a rare case of frequent torsades de pointes (Tdp) in a child with a novel AKAP9 mutation. A 13-year-old girl suffered from repeated syncope and frequent Tdp. An electrocardiogram (ECG) showed frequent multisource premature ventricular contractions with the R-ON-T phenomenon. The QTc ranged from 410 to 468 ms. The genetic test indicated a heterozygous mutation, namely, c.11714T > C (p.M3905T), in the AKAP9 gene, which is a controversial gene in long QT syndrome. After treatment with propranolol, recurrent syncope occurred, and the patient received an implantable cardioverter defibrillator (ICD). Due to frequent electrical storms at home, the child was additionally treated with propafenone to prevent arrhythmia. The antitachycardia pacing (ATP) function in the ICD was turned off, and the threshold of ventricular tachycardia (VT) assessment was adjusted from 180 beats/min to 200 beats/min. The patient was followed up for 12 months without malignant arrhythmia and electric shock.

CONCLUSION

Genetic testing may be a useful tool to determine the origin of channelopathy, but the results should be interpreted in combination with the actual situation. Rational parameter settings for the ICD and application of antiarrhythmic drugs can reduce the mortality rates of children.